FIELD OF THE INVENTION
The present invention relates to a portable card for use as a data carrying medium. The card in question may, for example, be a credit card for use in the business and banking field, or an identity card as used in control or security systems for example.
Data carriers may assume widely varying forms such as for example, a card proper, a ring, a key, a ticket, a slip, etc. For the sake of simplicity the term "card", which in any case is the applicable term in the majority of cases, will be used herein although it should be appreciated that this does not imply any limitation of the invention.